Poison ivy, perhaps? I apply calamine lotion and think no more of it until I notice the same rash on my abdomen, where my jeans button happens to sit. I’d known for 20 years that earrings made my lobes itchy, but why were my watch and jeans suddenly a problem?

The culprit is nickel, the most common metal allergen. It turns out that because I’m sensitized to it in one place, I’m likely to react to it elsewhere on my body.

It’s a chronic condition, so I’m stuck with it for life. But at least I am in good company: nickel allergy affects up to one in seven women. That means I have around two million Canadian sisters suffering along with me. Of course, nickel allergy affects men as well, but in smaller numbers.

A nickel reaction generally shows up as an itchy, red, bumpy rash where something containing the metal, such as a necklace, a watch, a ring or a pair of earrings, sits against the skin.

The incidence of nickel allergy shot up in the 1990s; it used to hover at about 10 per cent of women, but has grown to 14 per cent. That’s because of the popularity of body piercing, the most common cause of the reaction.

When the wrong type of piercing tool is used, corrosion causes the release of nickel ions, which can leach onto the skin. The same goes for studs used while the ear lobes are healing.

For those of us contending with the allergy, earrings, other piercings and rings are obvious triggers. But like my jeans fastener, other nickel encounters are less apparent.

A glasses wearer may not initially make the connection between a line of red bumps and contact with a pair of nickel-laden spectacles, while a woman may wonder what is happening to her as an underwire bra rests against her irritated skin.

Nickel allergy sufferer Kathy Weber of Stroudsburg, Pennsylvania recalls her also-allergic 9-year-old daughter’s reaction to a more obscure object. “She brought home her new trumpet – an instrument she’d been excited to play since kindergarten – and played it frequently over the next few days,” Weber says.

Her daughter soon developed itchy, blistering lips. Some quick Internet research uncovered a high nickel content in that particular mouthpiece. Kathy bought a poly-carbonate mouthpiece for her daughter and gave the nickel one to her trumpet-playing husband.

If you’re getting skin eruptions, you may wonder if nickel allergy is the cause. According to Dr. James Bergman, a Vancouver pediatric dermatologist and allergist, if it’s nickel allergy, the rash will typically show up as a well-defined, red area. Sometimes there will be a more general eczema reaction that spreads to other parts of the body, even where there was no direct nickel contact. But that’s not common.

Next: Prevention and avoidance

If you have either the rash or the eczema symptoms, but your doctor isn’t sure whether the reaction is to nickel or some other substance, you may be referred to a dermatologist for patch testing.

In this process, explains Dr. Charles Morton, a Vancouver dermatologist, “we take low concentrations of metals, chemicals, rubbers or whatever we think the irritant might be, put that under special tape, apply it to the patient’s back and leave it for 48 hours.”

If there’s a raised, itchy rash on the patient’s back, they can identify the allergen.

The good news for those who aren’t yet allergic to nickel is that it can be prevented. Research shows that, while there is some evidence of genetic predisposition, the most important factor by far in nickel sensitization is direct and prolonged exposure to high concentrations of nickel.

To curb nickel allergy, people should avoid buying products that will release high amounts of nickel (for example, nickel-plated jewelry).

Or, if you already have nickel-plated consumer items that you wish to continue to use, avoid prolonged skin contact with them. Fleeting contact with nickel is less worrisome.

In the United States and Canada, all the silver coins are nickel-plated steel, but they are unlikely to cause a rash if your contact with them is brief. Same goes for casual contact with faucets, house keys and doorknobs.

Because of the prevalence of nickel allergy, more than a decade ago the European Union adopted rules limiting nickel-release levels on the surface of consumer products intended for direct and prolonged contact with the skin. Unfortunately, there isn’t similar protection in North America.

Bruce McKean, the director of stewardship and sustainable development at the Nickel Institute in Toronto, explains this is because “we are so far removed from the nearly all offshore manufacturers who may be using nickel inappropriately.”

However, the Nickel Institute, whose role is to provide research on the effective use of nickel in manufacturing and production, “does try to educate manufacturers, branders and retailers, and work with dermatological societies and sponsor research to raise the profile of nickel allergy,” he says.

Heightened awareness and promising research proves that lowering everyday exposure to nickel can reduce sensitization rates. Perhaps, if manufacturers use appropriate alloys in all our fasteners, non-corrosive instruments are used in body piercing and our children avoid prolonged contact with nickel-releasing jewelry and fasteners, the next generation may be protected.

But for the sensitized, it seems, nickel will continue to surprise us. Remember that trumpet mouth piece that Kathy Weber gave to her non-allergic husband?

Well, within a week, Weber had the same itchy, burning lips that had plagued her daughter. “Being the ‘kissing couple’ that we are, I suddenly realized that my husband’s playing and subsequent kisses were causing a reaction,” she says.

The nickel had leached from the mouthpiece, to her husband’s lips, to Weber’s. “We quickly bought a replacement mouthpiece!” Weber says with a laugh.

There are no scientific studies that back up exquisitely sensitive anecdotes like these, but like with any long-time allergy-sufferer, Weber’s hunch is probably right. Dare we sound a hypoallergenic-trumpet? Avoid nickel now.